Problem: Simplify the expression. $ (3r^{7}+2r^{2}) + (-2r^{5}-4r^{4} ) - ( 7r^{5}+6r^{4}) $
Answer: Distribute any negative signs. $(3r^{7}+2r^{2}) + (-2r^{5}-4r^{4}) + (-7r^{5}-6r^{4})$ Since we are adding polynomials, we can simply remove the parentheses. $3r^{7}+2r^{2} - 2r^{5}-4r^{4} - 7r^{5}-6r^{4}$ Identify like terms. $ {3 r^7} + \color{#9D38BD}{2 r^2} - \color{#DF0030}{2 r^5} - {4 r^4} - \color{#DF0030}{7 r^5} - {6 r^4} $ Combine like terms. $ { 3 r^7} + \color{#DF0030}{ r^5} + { r^4} + \color{#9D38BD}{ 2 r^2} $ Add the coefficients. $3r^{7}-9r^{5}-10r^{4}+2r^{2}$